AbstractContext: .A 1000-s flare from a new hard X-ray transient, IGR J08408-4503, was observed by INTEGRAL on May 15, 2006 during the real-time routine monitoring of IBIS/ISGRI images performed at the INTEGRAL Science Data Centre. The flare, detected during a single one-hour long pointing, peaked at 250 mCrab in the 20-40 keV energy range. Aims: .Multi-wavelength observations, combining high-energy and optical data, were used to unveil the nature of IGR J08408-4503. was performed, and the detailed analysis of another major Methods: .A search in all INTEGRAL public data for other bursts from IGR J08408-4503flare is presented. The results of two Swift Target of Opportunity observations are also described. Finally, a study of the likely optical counterpart, HD 74194, is provided. Results: .IGR J08408-4503 is very likely a supergiant fast X-ray transient (SFXT) system. The system parameters indicate that the X-ray flares are probably related to the accretion of wind clumps on a compact object orbiting about 1013 cm from the supergiant HD 74194. The clump mass loss rate is of the order of 10-6 Mȯ yr-1. Conclusions: .Hard X-ray flares from SFXTs allow to probe the stellar winds of massive stars, and could possibly be associated with wind perturbations due to line-driven instabilities.

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.